This disclosure relates to thermoplastic compositions having improved scratch resistance, methods of manufacture, and articles prepared from the thermoplastic composition.
Lightweight thermoplastic materials that have a glossy or semi-gloss finished appearance are useful materials of construction for all or part of durable articles, such as molded or thermoformed articles ranging from hand-held electronics devices such as cell phones to exterior components of automobiles. Polycarbonate-based materials, with their high surface gloss capability, high transparency, and excellent impact strength, are highly useful for such applications. Stabilized, weatherable polycarbonate compositions can be of use for applications in which the article may be exposed to outdoors conditions of light and moisture. The use of weatherable polycarbonates can also provide color stability and surface finish properties that may be desirable in the articles, particularly those for use in the outdoors. Weatherable thermoplastic compositions, however, may have lower ductility and decreased processability, in addition to a higher manufacturing cost, and can therefore be less desirable for use in some applications where high ductility and thermoformability are useful.
Durability and abrasion resistance are also useful properties for a lightweight thermoplastic, for applications in which the exterior surface of the article may be subject to physical contact by other objects. For such applications, articles that are prepared from polymers such as polycarbonates are expected to withstand abrasion, e.g., when exposed to abrasive materials such as steel wool and cleaning agents, sliding on a surface, dropping, slipping it inside a pocket, rubbing against other items such as coins, keys, or the like. Polymer compositions with scratch resistance are therefore desirable in articles requiring a durable surface finish and appearance.
Accordingly, there remains a need in the art for a polycarbonate-based thermoplastic that has both excellent gloss retention and improved scratch resistance. The thermoplastic composition should also have other physical properties, such as weatherability, impact strength, ductility, and thermal flow characteristics for manufacturability by injection molding, extruding, and/or thermoforming that are comparable to or better than existing polycarbonate-based thermoplastic compositions.